D630 Audio Problems

When I was running Windows XP my speakers worked great. I upgraded to Windows 7 over the weekend and now have a problem with the Audio. I Only get sound out of one speaker, the 2nd one is dead.  I have uninstalled the driver and then when I reboot, windows 7 finds the new driver and installs.  It says it is working good. Any help on where to find correct driver with instructions on changing to it would be appreciated.

Thank You.

Jeff